1. Field of the Invention
The present invention relates to a multichannel access radio data communication system, more particularly to a multichannel access (MCA) radio data communication system wherein the users are station for performing radio data communication among users, a user at a terminal station receiving allocation of one of a plurality of predetermined channels to secure a channel assignment. Radio data communication on a channel is performed over a fixed occupied time T the channel being released after the elapse of a fixed holding time t (T&gt;t) after the completion of the radio data communication.
Radio systems for business use, for example, utilizing the MCA radio method are widely available. In such systems, both voice and data communication are possible, but the present invention refers in particular to radio data communication.
2. Description of the Related Art
As will be explained in more detail, a common MCA radio data communication system comprises a base station e.g., a central command office), a plurality of terminal stations (e.g.), movable terminal equipment, for engaging in radio data communication with the base station, and a control station (for providing radio communication channels between the base stations) and terminal stations. Further, the base station has a host computer, while the terminal stations have terminal computers.
When a first terminal station requests a communication, the control station assigns an idle channel from among a plurality of channels to the first terminal station for communication. When the first terminal station receives and secures the channel assignment communication with the base station can begin. When the first terminal station completes the communication, a line release operation is performed between the host computer and the first terminal computer, thereby releasing the channel in the MCA radio channel network as well.
When a second terminal station among a group of users at the same location as the above first terminal station wishes to start data communication immediately after the first terminal station completes communication, the second terminal station must go through the procedure for channel assignment all over again.
In the morning and evening when data traffic density is high wait time for channel assignment can be as much as several minutes to several tens of minutes, which does not allow quick data processing.
If, in one channel allocation, (assignment) a maximum 60 seconds of occupied time T is allowed and the data communication is completed in a short time (for example, 20 seconds), then the communication time given cannot be used to its maximum limit. In this example, there is the problem of the remaining 40 seconds being wastefully discarded. This causes call loss in a user.